Estimate solar panel count, production, incentives, and payback.
Turn a target system size into panel count, expected output, electricity value, total project cost, and a more useful long-term ROI view.
Estimate solar panel count, annual production, and simple payback
Start with the system size you want, match it to a panel wattage, then turn that setup into estimated annual production, electricity savings, and a simple installation payback.
- System size is usually discussed in kW, even though total production is measured in kWh.
- This version uses a built-in annual production assumption to keep the form simpler.
- Total project cost here is equipment plus installation labor before credits and rebates.
- This still ignores financing costs, maintenance, and battery replacement if storage is added later.
This page is meant for early planning. It turns a target system size into an approximate panel count, annual production estimate, electricity value, and a simple payback view using the assumptions you provide.
The federal tax-credit field is editable. If you need the current IRS description of the Residential Clean Energy Credit, use the IRS guidance page as the starting reference.
The calculator now handles a zero-size system correctly so production, savings, and panel count remain zero instead of inventing a panel.
An 8 kW residential system using 400 W panels needs about 20 panels before round-up effects. From there, the calculator estimates annual production, electricity value, and a simple payback range based on your cost and rate assumptions.
Results exclude financing, maintenance, inverter replacement, battery economics, roof constraints, local permitting, and utility-program rules. Treat the output as a planning estimate, not an engineering or tax determination.
Maintained by David K. ยท Last reviewed: July 23, 2026